Blackboard-eraser cleaner.



A. ILSTRUR BLAoxBoARn mmm CLEANER.

PPLICLFFION FILED DEC. 16, 1908. 925,478. 'i Patented June V.22. 1909.

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A. ILSTRUP.

BI-.AGKBOARD BRASBR CLEANER.

APPLIGATIQN FILED 1320.16, 190s.

925,478. yPatfanted June 22, 1909.-

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pierre` sans ARTHUR ILSTRUP, OF ST. CLOUD, MINNESOTA.

BLACKBOARD-ERASER CLEANER.

Specification of Letters Patent.

Patented June 22, 1909.

Application led December 16, 1908. Serial No. 467,857.

To all whom it may concern:

Be it known that I, ARTHUR ILsTRUP, a citizen of the United States,residing at St. Cloud, in the county of Stearns and State of Minnesota,have invented certain new and useful Improvements in Blackboard-EraserCleaners, of which the following is a speciiication.

My invention relates to machines for cleaning black-board erasers andhas for its object the provision of an improved machine of the typeemploying oppositely disposed oscillating arms to which the erasers aresecured so that their faces engage one another when the arms are broughttogether to beat the chalk dust out of them, said rods being normallyheld so that the-erasers on each pair are in engagement by means ofsprings and are actuated against the resistance of said springs intoposition so that the erasers are separated by means of cam wheelssuitably operated.

The construction and operation of my improved eraser cleaner will bedescribed hereinafter and illustrated in the accompanying drawings inwhich- Figure 1 is a side view partly broken away of my improvedmachine, F ig. 2, a detail view of the guide plate showing the beaterarms and arc-shaped bar in section, Fig. 3, a fragmental bottom planview, Fig. 4, a front view of one of the beater arms, Fig. 5, a sideview of a pair of arms, and Fig. 6, a view in elevation of the casingpartly broken away and in section.

In the drawings similar reference characters indicate correspondingparts in the several views.

1 indicates the base plate of my improved machine, that may be mountedon any suitable support (not shown) and has a longitudinal slot 2therein and a shaft 3 journaled thereon and operated by crank handle 4or other mechanism.

5 indicates two wheels secured to shaft 3 and having their rims formedinto a series of oppositely disposed blades 6, arranged in pairs withtheir ends toward the direction in which the wheels are rotated spacedfarther apart than their other ends, so that the sides of said bladesconverge as shown, and the front ends of the blades beveled as shown at7.

8 indicates an arc-shaped bar secured to base plate 1 adjacent to thetwo ends of slot 2 and having arms 9 pivotally secured thereto andarranged in pairs as shown. The outer ends of arms 9 are formed withoifsets 10 forming shoulders 11 and have spring clamping arms 12 securedthereto to engage the grooves 13 in the sides of the erasers 14, saidarms 12 being crimped as shown at 12a to more securely engage theerasers. The other ends of each pair of arms 9 are bent outwardly awayfrom one another as shown at 15 and then parallel with one another asshown at 16 and have rollers 17 j ournaled on their ends that engage theinner sides of blades 6.

18 indicates springs secured to the ends 16 of arms 9 that normally pushsaid ends 16 away from one another so that the erasers 14 on the otherends of the arms are in engagement.

From this construction it will be understood that when the wheels 5 arerotated by turning the crank handle 4 on shaft3 the rollers 17 areengaged by the blades 6 at their beveled ends 7 and by continuing therotation of the wheels the ends 16 of each pair of arms 9 are actuatedtoward one another so that the erasers 14 on the other endsV of the armsare actuated away from each other against the resistance of springs 18,until the rollers reach the ends of the blades and are released fromengagement therewith, when the springs 18 will throw the ends 16 of thearms 9 suddenly outwardly and the faces ol' the erasers 14 on the otherend of the arms will be thrown together sharply. By continuing thisoperation the chalk dust will be thoroughly removed from the eraserfaces. Ii' desired the rollers 17 may beprovided with any ordinaryconstruction of antifrictional bearings, suoli a construction beingobvious and'not necessary to be illustrated.

19 indicates a guide plate secured to base plate 1, arranged over wheels5, and provided with transverse slots 20 to receive the portions 16 ofarms 9 and having slanting offsets 21 to limit the outward movement oi'the arms under the impulse of springs 18 when there are no eraserssecured to any pairs of arms. The arms 9 and wheels 5 are inclosed in atwo part casing of which 22 indicates a semi-cylindrical member hinged,as shown at 23, at one end to the upper side of base plate l and havinga catch 24 at its other end to secure it in position; while 25 indicatesa funnel-shaped member secured under base plate 1 and 26 a cup or otherreceptacle removably IIO and replaceably secured at the smaller end ofmember 25 to catch the chalk dust.

Having thus described my invention what I claim is- 1. In an erasercleaner, arms holding the erasers pivotally secured and arranged inairs, springs secured to said arms to normally hold the erasers thereonin engagement with one another and means to swing the arms against theresistance of said springs.

2. In an eraser cleaner, a base having a slot, wheels mounted in saidslot having oppositely disposed, non-parallel blades secured thereto,arms holding the erasers pivotally secured and engaging said blades, andsprings secured to said arms to hold the erasers thereon normally inengagement with one another.

3. In an eraser cleaner, a base, an arcshaped bar secured to said base,arms holding the erasers pivotally secured to said bar and arranged inpairs thereon, springs secured to said arms to normally hold the erasersthereon in engagement with one another and means to swing the armsagainst the resistance of said springs.

4. In an eraser cleaner, a base having a slot therein, a rotatable shaftjournaled adjacent to said slot, wheels secured to said shaft andlocated in the slot, said wheels having oppositely disposed,non-parallel blades secured thereto, an arc-shaped bar secured to saidbase and located above the wheels aforesaid, arms holding the eraserspivotally secured to said bar and arranged in pairs thereon, said armsprovided with ends that engage said blades, and springs secured to saidarms to hold the erasers thereon normally in engagement with oneanother.

5. In an eraser cleaner, a base having a slot therein, a rotatable shaftjournaled adjacent to said slot, wheels secured to said shaft andlocated in the slot, said wheels having oppositely disposed,non-parallel blades secured thereto, an arc-shaped bar secured to saidbase and located above the wheels aforesaid, arms holding the eraserspivotally secured to said bar and arranged in pairs thereon, said armshaving their ends bent away from one another and then parallel andhaving rollers journaled on the ends of said parallel portions'thatengage the blades on the wheels, and springs secured to said arms tohold the erasers thereon normally in engagement with one another.

6. In an eraser cleaner, a base having a slot therein, a rotatable shaftjournaled ad- 'acent to said slot, wheels secured to said shaft androtatable in the slot, said wheels having oppositely disposed7non-parallel blades secured thereto, an arc-shaped bar secured to saidbase and located above the wheels aforesaid, arms holding the eraserspivotally secured to said bar and arranged in pairs thereon, said bladesto swing the erasers away from one another, a spring engaging each pairof arms to normally hold the erasers in engagement with one another, aguide plate secured to said base between the wheels and bar aforesaid,said guide plate having transverse slots therein to receive the ends ofsaid arms and offset portions to limit the movement of the arms underthe impulse oi the springs.

7. An eraser cleaner comprising a base having a slot therein, arotatable shaft journaled transversely of said slot, wheels secured tosaid shaft and rotatable in the slot, said wheels having oppositelydisposed, nonparallel blades secured thereto, an arc-shaped bar securedto said base and located above the wheels aforesaid, arms pivotallysecured to said bar and arranged in pairs thereon, the outer ends ofsaid arms having offset portions with shoulders to receive the erasers,spring clamping arms secured to said shoulders and having crimpedportions to engage the sides of the erasers, the inner ends of the armshaving outwardly bent portions and rollers journaled thereon to engagethe blades on the wheels when rotated to swing the erasers away from oneanother, a spring engaging each pair of arms to normally hold theerasers in engagement with one another, a

`semi-cylindrical casing hinged to the upper side of said base andinclosing the arms aforesaid, and a funnel-shaped casing hinged underthe base.

In testimony whereof I hereto affix my signature in the presence of twowitnesses.

ARTHUR ILSTRUP.

I/Vitnesses:

J. I. DONOHUE, J. E. C. ROBINSON.

